An electric vehicle etc. are equipped with a DC power source such as a battery or a fuel cell as a power source for driving a load of a motor etc., and this DC power source is connected to the load through a power source circuit. As a result, the electric vehicle etc. is provided with a service plug for manually disconnecting connection to the power source circuit in order to prevent an electric shock in the case of maintenance work etc. of the load.
As this service plug, for example, a service plug constructed so that a female housing in which a tubular peripheral wall part is erected along the outer edge of an annular groove formed in a base material, a male housing having a tubular peripheral wall part inserted into an annular groove of this female housing, a circuit terminal arranged inside the annular groove of the female housing and a short-circuit terminal arranged inside the peripheral wall part of the male housing are included and the male housing can be fitted into and removed from the female housing by a turning operation of a lever has been disclosed (see PTL 1). According to this service plug, by turning the lever in a direction in which the lever is pushed down, the male housing is fitted into the female housing and the short-circuit terminals are respectively inserted into the two circuit terminals and a power source circuit becomes closed. On the other hand, at the time of inspection, the lever is turned in a direction in which the lever is pulled up and the male housing is removed from the female housing and thereby, the short-circuit terminals are respectively separated from the two circuit terminals and the power source circuit becomes opened and an electric shock etc. are prevented.
Incidentally, this kind of service plug is generally installed in an out-of-sight position accessible from the inside of a vehicle body. For example, when a battery is received under the floor, the service plug is installed in the floor panel side of the lower side of a seat cushion, and work in narrow space of the lower side of the seat cushion is done when a plug body is detached in inspection and maintenance etc. As a result, it becomes difficult to properly position the male housing with respect to the female housing and there is fear that workability decreases.
In this respect, a circularly arcuate regulation member extending higher than the peripheral wall part of the female housing from a part of the peripheral edge of the annular groove of the female housing is erected in the service plug of PTL 1. Consequently, when the male housing is attached to the female housing, the male housing is moved in a direction intersecting with an insertion direction of the short-circuit terminal and thereby, a movement position of the male housing is regulated by the regulation member and it becomes easy to position the male housing with respect to the female housing. Also, a projecting bar projecting along a fitting direction is formed on the peripheral wall part of the male housing and this projecting bar is guided inside the annular groove in a state of being fitted into a groove formed in the peripheral wall part of the female housing and thereby, alignment between the female housing and the male housing is facilitated. Consequently, the plug body can be attached and detached easily well even when the service plug is installed in space difficult to make a visual check, for example, the lower side of the seat cushion.